.\"
.\" Copyright (c) 2003 Bruce M Simpson <bms@spc.org>
.\" All rights reserved.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\"    notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\"    notice, this list of conditions and the following disclaimer in the
.\"    documentation and/or other materials provided with the distribution.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
.\" SUCH DAMAGE.
.\"
.Dd July 21, 2003
.Dt PMAP_PAGE_EXISTS_QUICK 9
.Os
.Sh NAME
.Nm pmap_page_exists_quick
.Nd determine if a page exists in a physical map
.Sh SYNOPSIS
.In sys/param.h
.In vm/vm.h
.In vm/pmap.h
.Ft bool
.Fn pmap_page_exists_quick "pmap_t pmap" "vm_page_t m"
.Sh DESCRIPTION
The
.Fn pmap_page_exists_quick
function is used to quickly determine if the page
.Fa m
exists in the physical map
.Fa pmap .
It is typically called from the VM paging code.
.Sh IMPLEMENTATION NOTES
The PV count used above may be changed upwards or downwards in future;
it is only necessary that
.Dv true
be returned for a small subset of pmaps for proper page aging.
.Sh RETURN VALUES
The
.Fn pmap_page_exists_quick
returns
.Dv true
only if the PV entry for the physical map
.Fa pmap
is one of the first 16 PVs linked from the page
.Fa m .
.Sh SEE ALSO
.Xr pmap 9
.Sh AUTHORS
This manual page was written by
.An Bruce M Simpson Aq Mt bms@spc.org .
